Water Supersolid Skin

Abstract

Skin molecular undercoordination not only disperses the quasisolid phase boundary but also derives supersolidity that is hydrophobic, less dense, viscoelastic, repulsive, and thermally stable.• The supersolidity and quasisolidity defines the anomalies of water skin when interact with other objects. • The skin supersolidity increases with its curvature but drops when heated due to depolarization. • Electrostatic repulsivity and elasticity claims the superhydrophobicity, superfluidity, superlubricity, and supersolidity at the contacting interface.Abstract Consistency in experimental observations, numerical calculations, and theoretical predictions revealed that skins of 25°C water and −(15-20)°C ice share the same attribute of supersolidity characterized by the identical H-O vibration frequency of 3450 cm −1 . Molecular undercoordination and inter-electron-pair repulsion shortens the H-O bond and lengthen the O:H nonbond, leading to a dual process of nonbonding electron polarization. This relaxation-polarization process enhances the dipole moment, elasticity, viscosity, thermal stability of these skins with 25 % density loss, which is responsible for the hydrophobicity and toughness of water skin and the superfluidity in a microchannel.